Speedball

Robbie Baldwin was an angst-ridden Springdale Connecticut high school student who grew up under the often smothering guidance of his parents. His father wanted him to go in law while his free-spirited mother hoped he would go into arts. After school, he interned at Hammond Labs.
Robbie snuck in to watch an experiment that tapped an extra-dimensional energy source, and was accidentally irradiated by it when the energy went out of control. The energy gave him superpowers: Whenever Robbie was hit with an impact above a certain strength, he'd become surrounded by a protective kinetic energy field that manifested in the form of a more muscular body, a spandex costume, and floating 'bubbles' in the air around him. When he was in 'Speedball mode,' any impact against him caused him to bounce instead of harming him. He could also harness this energy and direct it more forcefully, or alternately use it as a bubble/shield to protect others, catch others, and even stop moving objects, like bullets, in mid-air. Speedball now serves as the mentor to the Young Avengers.